General wireless terminals may be used regardless of the movement and location of the user. In addition, the wireless terminals have recently been used for various purposes, such as videos or wireless data, as well as a voice service. Accordingly, the wireless terminals that adopt functions for processing a variety of information at a high data transmission rate have been developed. Therefore, in the case of using the wireless terminals that are mainly driven by the power from a mounted or embedded battery, a power control method for reducing the power consumption, even with the same operation, is required in order to increase the operating time without the supply of power from the outside.